Nationally Significant Ag Land, 2016 - American Farmland Trust

The conversion of agricultural land to more-developed uses jeopardizes food security and ecosystem integrity. However, nationally consistent, high-resolution spatial data on agricultural land location and change have been largely unavailable. Through a project titled Farms Under Threat, American Farmland Trust and Conservation Science Partners mapped the extent of and change in agricultural lands within the conterminous U.S. between 2001 and 2016, producing layers that capture land cover/use and agricultural land productivity, versatility, and resiliency (PVR). This analysis used data from a number of sources, including USDA NRCS National Resources Inventory (NRI), USGS National Land Cover Database (NLCD), NRCS Soil Survey Geographic Database (SSURGO), and NRCS Digital General Soil Map of the United States (STATSGO). These data provide an improvement over previous efforts by: harmonizing NRIs ground-based estimates of agricultural land with NLCD remote sensing; mapping agricultural land conversion in a consistent way over time; and mapping new land- use classes including low-density residential, woodlands associated with farms, and grazing on federal lands. We found that, of the major land cover/use classes, agriculture dominates the continental US landscape. Yet, from 2001-2016, 11 million acres of agricultural land were converted from agriculture to more-developed land uses. Of these 11 million acres, more than 4 million were converted to urban and other highly developed (UHD) uses, while nearly 7 million acres went to low-density residential (LDR) land use. Compounding these impacts, 4.4 million acres of the nations highest-PVR lands were converted to UHD and LDR land uses. These trends are likely to continue, as agricultural land in LDR areas was 23 times more likely to be converted to UHD than other agricultural land. Additional findings from the analysis are available in the report (https://farmlandinfo.org/publications/farms-under-threat-the-state-of-the-states/) and on the website (http://www.farmland.org/farmsunderthreat). Nationally Significant agricultural land is the land best suited for long-term production of food and other crops. To identify Nationally Significant land, we calculated a minimum productivity, versatility, and resiliency (PVR) value threshold. All agricultural land with PVR values above this threshold was classified as Nationally Significant and has an image value of 1). Areas which do not represent Nationally Significant land have a value of 0. A value of -9999 indicates data are not available for that area.